Electrical discharge device



Jan. 20, 1931. w. F. HENDRY ELECTRICAL DISCHARGE DEVICE Filed May visa.y 1927 s sheets-sheet 2 Inventw' una.

E Attorney w. F. HENDRY j,

. lELECTRICAL DsCHARGE DEVICE Jan. 2C, 1931.,l

Filed May 19. 1927 's sheets-sheet El l I, InKvenzvfor n Y Attorney Patented Jan. 20, 1931 UNITED STATES PATENT OFFICE Y WILLIAM r. HENDRY, or ossINING, NEW YonmpAssIGNo'R, BY MESNE Assrefrnrunrrs;,y

TO MANHATTAN ELECTRICAL SUPPLY COMPANY, INC.,: OF JERSEY CITY, NEW JERSEY, A CORPORATION F NEW JERSEY ELECTRICAL DISCHARGE :DEVICE Application mea may 19, 1927. seria1`No.,192,e5a.

This invention relates to velectrical relays y and relates more particularly to electrical More speciically,`I have found that an electrical discharge tube having coldelecv trodes can be so constructed'as tfo be capable of use as a relay for repeating electrical signals or disturbances. Good results may be secured with such tubes when constructed with a large electrode and a smallelectrode. While the materials from which theseelectrodes are made are notnecessarily limited,

large electrodes of aluminum and small electro-des` of carbonihave been found to give good results. The small electrode is mount-l ed opposite the vlarge electrode and lis surrounded by or mounted on a disc of mica or other insulating material which is capable of withstanding the heat developed by thel discharge occurring in thetube. The large electrode preferably isformed into the shapev of a hemisphereand positioned adjacent to the mica disc, which isv of approximately the same diameter as vthey hemispherical elec-.z

trode.-

As thus far described, the tube similark to the tube disclosed in the copending application of Lewis SjBaker, Serial No. 61016,

`filed October ,7, 1925. The present construction, however, involves the addition of a` control electrode to a tube of the foregoing construction. This electrode may be in the form of an annular ring and be mounted directly on the outer edge of the mica disc.,

The entire electrode assembly is enclosed in an envelope of glass or other material which is filled with some gas. such as one of the rases of the rare gas group, for example,

neon or helium, at low pressure. This pressure may be of the order of a few milli; 'n

meters of mercury, for example,l -in the neighborhood of two to ten millimeters. 4

I have found that when current is passed between the two main electrodes of a tube constructed in accordance with the foregoing disclosure, by means of an alternating current passing through the tube is rectified and limited to a certain value.

' rentsour'ce of fairlyr high potential, the cur-V According to this invention, I have found"` that kif the third electrode be grounded the' current through the' tube will immediate;V ly be increased in value by a relatively large amount. This ground need not be an @L l 4, tremely low resistance ground,rbut on the' contrary may be an extremely high rgsist- Y ance ground. For example, I have found f that if the lead-in wire attached to the third electrode be touched by the hand of a per-y son, the currenty through the tube will imv i mediately be increased. This result also'can i,

be secured in many cases merelyl by touching` the leadin wire of a third electrode to the table on `which the tube operating apparat-us is positioned. p While I have described the above men. tioned 'tube as having the third electrode mounted on the mica dise, it need noty necessarily be Vmoimtedthereas the. tube will also function successfully if the third electrode be made of wire gauze and be positioned i between the mica disc and 4the largeelec? trode. The wire gauze may be flat and paral-y lel with the mica disc or it may be made in hemispherical form similarly to thelarge electrode. Likewise, the large electrode need not'nec'essarily be hemispherical as a fiat I.

electrode may be used likewise. I have found also that a ,tube can successfully be constructed wherein both electrodesare of the same size. In sucha tube each of the electrodes may be mounted on a mica disc or be surroundedby a lmica annulus, and "be positioned opposite each other a suitable distance apart, with a gauze electrode mounted between the two electrodes.. I have found that the disc electrodes may be made, forexample,

of carbon in the form ofa shortv cylinder of t of tube the vmain source of potential Stfa trod d be applied between the two large eleces.

' I have found in connection with tubes of this general construction that a control of the current between the two main electrodes can be secured by placing a. bias potential on the third electrode, for example, by placing a battery between it and one of the main electrodes. Likewise by placing a source of signal energy between t e third electrode and one of the main electrodes, a control of the current through the main electrode circuit, responsive to the signal current, can be secured. Inthe first type of tubewhich I mentioned above, the control circuit preferably would be inserted between the third electrode and the small electrode.

While the mode of operation of the tubes I have described is not absolutely clear as yet, I advance the following theory, if not the correct one, a ossible one, which seems to be substantiate by various tests and the actions of the tubes.

During the operation of the tube l'on alternatingcurrent a space charge isA built up around the anode, which space charge extends to the mica disc and imparts a charge to it. This chargek is positive and serves to attract electrons durlng the operation of the cycle when the sma l tive, thus reducing the migration of electrons between the two main electrodes and which results in a decrease in current flow between' the two main electrodes. By placing a metal ring on the mica disc and conynecting the ring to ground, the positive charge upon the disc is dissipated and upon ring and one of the main electrodes, which would result in a change in current flow between the two main electrodes. It appears that this static charge also can be dissipated by placing a metal ring adjacent to, but vnot touching the insulating disc. Other objects and advantages of the invention will appear more clearly from a considerationy of the following description taken in connection with the accompanying drawings. n

In the drawings, Fig. l illustrates a tube constructed in accordance with my inventiony whereina large hemispherical electrode and a small button electrode are employed.

Fig. 2 illustrates a circuit arrangement for the tube shown in Fig. 1.

Fig. 3 represents a modification of the tube shown in Fig. 1. Fig. 4 illustrates a circuit arrangement for the tube shown inFig. 3.

electrode is nega- '1 In Fig. 1 reference numeral 1 indicates an envelope of glass or other suitable material lwherein are mounted two electrodes 2 and 3 respectively. Electrode 2 is attached to a lea -in ro 6-which passes through a glass sleeve 8, which sleeve in turn is attached to the envelope l. Lead-in rod 6 is attached to wire 12 which is sealed through the envelope 1. Electrode 2 is supported in similar fashion by a lead-in rod 7 which passes through a glass sleeve 9 which is attached to envelope 1. Lead-in rod 7`communicates with the exterior of the glass envelope by means of a lead-in wire 10. Positioned underneath elec trode 3 is a mica disc 4, this disc being held between the electrode 3 and the glass sleeve 9. Mounted u on mica disc 4 is an annular electrode, or 'grid 5 which communicates with the exterior of the glass envelope by means of a lead-in wire 11.

Within the envelope lis a filling of rare gas at low ressure. The electrodes 2 and 3 are yprefera ly madeof aluminum and carbon respectively, but other materials may be used with but slightly diierent results. Copper or iron might be substituted for the aluminum velectrode and nickel or the like might be used in place of carbon. While a fillin or rare gas such as neon is preferable for est results, other gases or mixtures of gases may be use I f In Fig. 2 the main circuit, which will hereinafter be referred to as the plate circuit, is between electrodes 2 and 3, through load 18 and battery 17. The control or grid circuit is between electrodes 3 and 5 through batter 20and key 19. Shunted around the contacts of key 19 is a condenser 21 which serves to reduce sparking at the contacts of thepkey 19.

It is to be understood that alternating current may be used in place of battery 17, if desirable, for certain types of work, as thev action of the control electrode will also regulate the flow of alternating current in the plate circuit similarly'to direct current.

` Fig. 3 represents a tube substantially similar to that shown in Fig. 1 except that the control electrode 5 is positioned between the large and small electrodes and is supported by a mica disc 13, which is in turn secured by three posts 14 which are mounted upon mica disc 4.

In Fig. 4 the plate circuit includes electrodes 2 and 3, load 18 and battery 17 while 'the control circuit consists of electrode 5 which is connected to a key 19 which has one I contact connected through to ground.

In Fig. 5 two electrodes 15 and 16 of equal size are mounted upon mica discs 4 which are battery is nect the lead-,inwire of electrode 5 to ground',-`

` tremely high ways,

i llfrsaeae supported substantially'the same as electrode 3 of Fig. 1. Positioned between the two electrodes is the control electrode 5 which ,con` sists of a wire screen mounted on a mica annulus 13. The mica annulus 13 is supported betweenmica discs 4 by means of posts In Figs. 6 and 7 the plate circuit consists of relectrodes 15 and 16, load 18 and 'battery 17, while the control circuit comprises battery 20, key 19 an-d electrodes 5 and15. Con'- denser 21 is shunted around the contacts of key 19 for the purpose of preventing excessive sparking. This condenser need not necessarily be included as the circuit will function very well Withoutit. The diagram of Fig. 7 is substantially the same as that shown in Fig. 6 except that the polarity of battery 17 is reversed. f

The o peration of the device shownin Figs.

, 1 and 2 is as follows: Battery 17 supplies current which causes a discharge between electrodes 2 and 3. This discharge is limited to a certain value for any givenr potential of the control electrode 5. When the keyv 19 is closed the potential of the battery 20 is applied to electrode 5 which causes a change in the iiow' of current between electrodes 2 and 3. While:` the circuit is shown as having battery 20 biasing the third electrode 5, the circuit will Work excellent-ly without the battery.` When no used it is necessary merely to conwhen immediately the current flow between the two electrodes 2 and 3 will be increased greatly. The connection to groundneed not be of'a low resistance, but may be of an eX- resistance asitk has been found, for instance, thatthe conductivity oifered by the human body is suiiicient to cause a marked change in the value of the current iowingbe` tween electrodes 2 and 3. Likewise it has been found that a similar effect can be secured by touching the leading-in wire of electrode -5 to a very small change in resistance of the circuit between electrode 5 and electrode 3 will cause a very marked change in two main electrodes. This phenomenon might be4 made use of-in many and varied for example, the device might be used as a very sensitive burglar alarm by connecting a wlre from electrode 5 to the knob of a door or other metal object or placing it in some position `where an unacquainted person tially current betweenthe radio.

would come'in contact withitfwhich: contact would cause a current rto flow between the mainv electrodesjand through load device.` 18

and cause a bell to'be rung or other signalto l A y 7U b-actetdc 'Because of the .peculiar operating charac` l teristicsof thistube a verym'inute potential change in thecontrol cireuitfwill cause 1a large change ofv current inthe main` circuit. -With proper conditions this" change is' extremely violent. For, example, when theele'ctrode is left disconnected yand theA potential ofvbattery 17 is suchthat electrode'2 is positive withl respect to 4e1ectrode-3, if the potential of the' battery be vproperly regulated practically no current will flow between electrodes2 and 3. However, immediately upon the grounding of electrode 5 through a resistance even as high or,` higher than thatof the human body the current through `the mainfelectrodes immediately increases :to a relatively large amount. The tubes and circuits illustrated in the remaining figures all operate in substanthe same manner and hence it is believed unnecessary to go `into a detailed explanation thereof. vIn connection' with a par,-y

ticular tube such as shown in Fig. 5, it might be said that with the batteries connected as shown in Fig. 6 that the current in the plate circuit varies in a straight lineratio with respect to va change of potential of battery 20.v

For example, zit was found that with `battery `r17 having a ypotentialfof 500 volts' and bat- 20! having a potential of 270 volts, conc ioo tery

nected with the positive terminal to the con-l trol electrode 5, that the current in the main electrode circuit was ten milliamperes, while with the potential `of battery y20 at 27 0 volts, with the negative terminal connected to elec.- trode 5, the main electrode current was 47 milliamperes.

los'

With battery 2O connected between electrodes 5 and 16 itfwas found that` with the potentiall of battery 17 at 495 volts and thaty of battery 20, 112 volts, with thel negative terminal connected to velectrode 5,

that the plate current was 1.65 milliamperes';

whileA with the potential of batteryv20 equal f to 125 volts and the positive connected to electrode 5, a plate current of 3.3 milliamperes was obtained. With, atube of the type Y was found that the current.I l

shown in Fig. 3 it through the platev circuit varied directly' in proportion to the potential ofv thev control electrode 5 up to a certain value, when a point was reached where further increase 1n v.the of the electrodey 5 did not-cause a change in the main electrodev potential corresponding current. 'Sucha tube would therefore be suitable for the detectionof certaintypesof signals, for example, such as those used in It will be obvious to those skilled in the art that the invention iscapable of a wide variety of modifications and adaptations and that the.' present' disclosure is intended merely to i1-.l

lustrate its nature without limiting its scope which is defined inthe appended claim. 4

Vh'at I claimis: di y In an electrical discharge device, a gas filled 5 "nvelope, a llemisfphericalcathode in sid envelope, an anode in said envelope mounted `at a point substantiallv equidistant from "all points of saidcathode, leading-in rwlres :forvr saidanode and cathode, 'an insulating disc of ubstantially the sanie'diameter'as saidcath-v ode held below said cathode, and an annular control electrode positioned on said disc. y

In' testimony wl1ereof,WVi1liam F. Hendry has signed his name to this specification this g5 17th day of May, 1927.

`VILLIAKM F. HENDRY.` 

